21550441 has 12 divisors (see below), whose sum is σ = 24977520. Its totient is φ = 18436160.

The previous prime is 21550409. The next prime is 21550447. The reversal of 21550441 is 14405512.

It is not a de Polignac number, because 21550441 - 2⁵ = 21550409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21550447) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 211 + ... + 6568.

It is an arithmetic number, because the mean of its divisors is an integer number (2081460).

Almost surely, 2^21550441 is an apocalyptic number.

It is an amenable number.

21550441 is a deficient number, since it is larger than the sum of its proper divisors (3427079).

21550441 is a wasteful number, since it uses less digits than its factorization.

21550441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6824 (or 6807 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 22.

The square root of 21550441 is about 4642.2452541847. The cubic root of 21550441 is about 278.2821738554.

Adding to 21550441 its reverse (14405512), we get a palindrome (35955953).

Subtracting from 21550441 its reverse (14405512), we obtain a square (7144929 = 2673²).

The spelling of 21550441 in words is "twenty-one million, five hundred fifty thousand, four hundred forty-one".